Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Wireless sensor networks include sensor nodes having a plurality of sensors and a receiver. The sensors are typically linked by a wireless medium to perform distributed sensing operations. The wireless sensor network applications require energy efficiency. As energy consumption in a wireless sensor network may be a problem, wireless sensor networks are typically formed in low power consumption clusters, where a cluster head node is typically selected at a remote end of the wireless sensor network. Since there is a difference between a distance from the cluster head node to a base station and other clusters to the base station, energy consumption of the clusters is unbalanced. Alternatively, data collection may be performed based on node-distributed control. In either case, performance of a network-clock synchronization operation may be necessary.